TDS and conductivity converter
Convert between electrical conductivity and TDS with an adjustable conversion factor, and see the typical water classification for the result.
Results
| TDS | 960 mg/L |
|---|---|
| Conductivity | 1 500 µS/cm |
| Conductivity in mS/m | 150 |
Roughly 960 mg/L TDS — within the SANS 241 aesthetic limit, palatability declining. This is a concentration, not a verdict on safety: TDS carries no information about bacteria, nitrate, fluoride or metals, so it cannot establish that water is fit to drink. The EC–TDS factor depends on the ion mix, and the two common instrument scales run the opposite way to most people’s guess: ~0.5 for NaCl-dominated water, ~0.65–0.7 for the mixed-salt (“442”) scale meant for natural waters. Handheld TDS meters measure conductivity and apply a fixed factor — check which scale yours uses before comparing readings.
Formula used
TDS = EC × f
EC (mS/m) = EC (µS/cm) ÷ 10
- TDS
- total dissolved solids, mg/L
- EC
- electrical conductivity at 25 °C, µS/cm
- f
- conversion factor: ~0.5 NaCl scale, ~0.65–0.7 mixed-salt (442) scale for natural waters (default 0.64)
The factor depends on the ion mix and on the instrument scale: ~0.5 for the NaCl scale, ~0.65–0.7 for the mixed-salt (442) scale intended for natural waters, with 0.64 a reasonable general-purpose value for South African borehole water. Handheld TDS meters measure EC and apply a fixed factor — check which scale yours uses before comparing readings. Conductivity is temperature-sensitive; meters normally report the 25 °C-compensated value. TDS is an aesthetic and process number: it cannot establish potability.
Equipment for this duty
Send the water analysis and duty point, and the branch confirms exact selections, pricing and lead times — usually within one working day.
Request a quoteResults are indicative engineering estimates based on standard formulas and typical assumptions. They are not a design service; confirm any design against a full water analysis and the relevant manufacturer’s data.